Clamp for paper cutters



Dec. 3, 1940. w. R. EPKLLER ETAL CLAMP FOR PAPER GUTTERS s Shets-Sheet 1 we Mm O E T N m Ema 0 w fl w JMWA 8/. 2 I MW Dec. 3, 1940.

. SPlLLER ET AL I CLAMP FOR PAPER CUTTERS Fil ed Nov! 21, 1959 3 Sheets-Sheet 3 BY Joy/7 ,8. Leann/1 Mow 0f 1nd ATTO 5 Patented Dec. 3, 1940 CLAMP FOR PAPER CUTTERS William R. Spiller and John R. Lehman, Dayton,

Ohio, assignors to Harris-Seybold-Potter Com pany, Cleveland, Ohio, a. corporation of Delaware Application November 21, 1939, Serial No. 365,524

18 Claims.

This invention relates to improvements in clamps for paper cutters, and has reference primarily to power operated papercutters of the guillotine type in which the clamp is actuated automatically when the operator throws a control for causing the knife .to descend and make a cut. The invention has to do with the clamp structure, with the pull bars for the clamp and with an auxiliary means for operating the clamp.

One object of the invention is the provision of pull bar means for the two ends of the clamp so connected and mounted that the'pull bars never contact the paper piles on the machine table, the lubricant for the pull .bars does not get onto the table or the work supported thereupon, and the uneven stress on the pull bars when a narrow pile at one side only of the table is cut does not cause the adjacent pull bar to be canted over, disturbing the pile and making the cut uneven. I

Another object of the invention is the .provision of auxiliary means, under control of the operator, for operating the paper clamp independently of the cutter knife with but a slight effort on his part, that is just enough to enable him to gauge the clamp pressure by the feel of the control means.

A further object is the provision of a novel clamp structure wherein the paper contacting elements consist of aseries of presser feet on the lower ends of shoes which have a certain independence of movement both vertically and in a sidewise tilting direction, so that a series of piles of somewhat different height maybe accommodated simultaneously and an even pressure may be exerted upon piles which are higher along one edge than the other, as for example piles of booklets, the bound edges of which are higher than their opposite edges.

4 Other objects and features of novelty will appear as we proceed with thedescription of those embodiments of the invention which, for the purposes of the present application, we have 45 illustrated in the accompanying drawings, in

which I Fig. 1 is a plan view with certain parts broken away and others shown in section of a paper cutter embodying the invention.

Fig. 2 is a vertical sectional view of the same taken substantially on the line 22 of Fig. l.

Fig. 3 is a fragmental front elevational View of a portion of the structure shown in Fig. 2.

I Fig. i is a detail sectional view taken sub- 66, stantiallyon the line 4,4 of Fig. 3.

Fig. 5 is aview similar toFig- 3 showing a slightly modified form of the invention.

Fig. 6 is a fragmentahside View of the con struction of Fig. '5. Y i

Fig. 7 is a fragmental elevational View of the 5 clamp bar. a r y I Fig. 8 is a sectional view taken substantially on the line 88 of Fig. 7, showing the shoe in normal position, and

Fig. 9 is a similar view showing the shoe raised somewhat as it would be after the clamp had engaged a paper pile.

In the, drawings we have shown so much of a paper cutter :asis necessary to illustrate the present invention. The invention however is directed only to the clamp and its operating mechanism. In Figs. 1 and 2 there is shown a base It upon which is mounted a work table II and frame side members 12. Suitably mounted in the basethere is a shaft 13 which carries a fly-wheel l4 and a belt pulley l5 from which the machine takes its, power. I6 is a friction clutch of suitable form which is adapted when in operative position to connect power shaft l3 with shaft H, the two shaftsbeing in alignment. Through suitable gearing, not herein illustrated, power is transmitted from shaft IT to shaft 18 by means of which the knife bar l9 (Fig. 2) is lowered'to makeythe cut and then returned to the top of its stroke. Conventional means, also not shown herein, are used to throw out clutch 16 after shaft [8. has made one complete revolution for lowering the knife bar and raising it again to its uppermost position.

The paper clamp, which comprises a beam 20 and a: hollow bar 2| integral therewith, slides vertically directly behind the knife bar, as shown inFig.v 2. In the frameside members 12 on. opposite sides of the machine there are formed vertical grooves 22 facing'the inner surface of these frame members. Grooves 22 terminate above the surface of table II a distance at least as great as the height of the maximum pile which may be accommodated in the, machine, in other words a distance substantially equal'to the throw or stroke of the clamp. Below that point and communicating withthe said groove there is a hole 23 through theframe side member extending down below the table. On each side of the machine a pull bar;24 is mounted to slide in groove 22 and in hole 23, the latter receiving the pull bar with a sliding fit all around. Hole 23 may be broached or otherwise formed in the. housing, and is prefer-ably rectangular.

l leretofore clamp pull barsyhave been located 55.

which is more or less oily and dirty. If the bars. were wiped free of oil the resultant wear and,

Fur-

increased friction would be undesirable. thermore there was always the danger that short piles would be gauged to the pull bar itself, which usually was recessed slightly from the face of the housing, so that the pile would not be square with the knife, again causing inaccurate work. It will be clear that our invention, by placing the pull bars behind the surfaces of the housings, overcomes these difficulties while maintaining the pull bars close to the'ends of the clamp and providing them with accurate guides.

The upper end of each pull bar is fastenedby means of screws 25 or the like to one extremity of beam 29, the lowermost fastening being spaced upwardly from the bottom surface of the .clamp a distance at least as great as the stroke of the clamp. The ends of the beam 20 extend into the grooves 22 and are guided thereby. The beam 21] also overlaps one or bothsides of groove 22, as indicated in Fig. 2, and has a slide bearing thereupon. A relief is formed at 26, Figs. 3 and 5, and at the lower portions of the clamp there are furtherbearing surfaces 21 which are adapted to slide upon the smooth inner surfaces of the frame side members. The fastenings 25 may be continueddown to the upper end of relief 25 if desired. The lowest one of these fastenings and likewise that part of beam 20 which entered groove 22 must terminate a distance above the bottom surface of the clamp at least as great as the clamp stroke in order that the bottom of the groove shall not interfere with the descent of the clamp to the level of the table.

The pull bars 24 extend downwardly a considerable distance beneath the table and near their lower extremities carrypins 28. These pins are straddled by the bifurcated-lower ends of links 29, the upper ends of which are pivoted to cranks 30 which are pinned to a rock shaft 3| that is oscillatably supported in bearings in the base of the machine. Suitable means are provided for swinging shaft 3| anti-clockwise as viewed in Fig. 2 automatically when the knife movement is started, so as to push downardly on the pins 28 and thereby operate the pull bars to lower the clamp somewhat in advance of the knife movement, and to relieve pressure on thepins 28 after the cut is made so that the counterbalancing means for the clamp may act to raise it again. This counterbalancing means may conveniently consist of spiral springs 32 located in vertical bores in the machine frame acting upon arms 33 secured to the clamp, one such arm only being shown. In order to maintain the two ends of the clamp always at the same level a rock shaft 34 journaled in the frame side members is connected with rearwardly extending projections 35 at the ends of the clamp by means of crank hich are flush'with' the inner surfaces of the frame side members [2. In the modification of Figs. 5 and 6 the side gauges are marked 9', and instead of terminating at the rear wall of the frame side members l2 they continue forward substantially to the line of cut, being recessed into the side frame members. In this case there are no holes 23 formed entirely within the frame side members, but the grooves 22 are continued down through the level of the table and are closed for the required distance above the table by the side gauges 9'.

Heretofore it has been usual to provide means for depressing the clamp actuated independently of the shaft 3; l'by foot pressure of the operator.

The clamp is quite heavy and its counterbalancing springs are'therefore relatively stiff. Hence the effort which the operator must exert is considerable.- In accordance with our present inventionthe auxiliary clamp operating mechanism is actuated principally by power, thereby relieving the operator of this burden.

In the base of the machine there is a shaft 3! which is. driven continuously from shaft l3 by suitable gearing. 38. A lever 39 is swiveled on shaft 31.50 as to be normally unaffected by the rotation of that shaft. The forward end of this lever is bifurcated and straddles one of the pins 28, as shown in Fig. 2. A drum 4!) is keyed to shaft 31 adjacent lever 39, and this drum is adapted to be engaged externally by friction pads 4| carried upon a semi-circular arm 42 which is pivoted at 43 upon the lever. The opposite end of this arm is pivotally connected at 44 with a short link 45 that is mounted upon a pivot 46 on the inner end of a foot lever 41 pivotally mounted in ears 48 on the base of the machine. A set screw 49 may be mounted in a lug on the side of lever 41 so as to limit the movement of the lever in one direction.

When an operator desires to lower the clamp alone, as in'setting the back gauge for a cut, he applies slight foot pressure to the pedal at the front end of lever 41, bringing the pads 4| into engagement with the drum 40. There will be more or less friction between these pads and the drum depending upon the degree of foot pressure exerted, but enough friction may be permitted to act to swing arm 42 anti-clockwise, thereby exerting a. downward pull on pivot 43 and pulling down the forward end of lever 39 to depress the clamp. When the pads come into engagementwith the drum upward movement of pivotj44 independently of pivot 43 is prevented, so that the foot pressure exerted upwardly on pivot 44 tends to'swing the lever 39, and this tendency is proportional to the friction brought to bear upon the drum, Consequently the feel of the foot pedal enables the operator to gauge the degree of friction which he is causing to be exerted on the drum, and likewise the resulting clamp pressure.

Referring now to Figs. 7, 8 and 9, where the structure of the clamp itself is illustrated in detail, it will be noted that the hollow bar 2| has a forward wall 50 integral with the beam 20 and a removable wall 5! attached to a depending rib 52 by screws 53. These walls 50 and 5| have bottom flanges 54 and 55, and they are connected, although in spaced relation, by screws 56, collars 51 being mounted onthese screws between the flanges.

A series of shoes 58, preferably formed of metal, are mounted within the hollow bar 2! and project beneath it forengagement was the work. These shoes are mounted so 'as to be capable of indi-- '54 and 55.

vidualtilting movement in a transverse plane as well as individual up and down movement. There is no movement possible in any other direction however. In the embodiment illustrated that portion of eachshoe which lieswithin the hollow beam 2| is I-shape in cross section; and comprises a vertical web 60, an upper flange 6| and a lower flange 62. Below the flange 62 there is a second web 63 extending downwardly between the flanges 54 and 55 of the hollow bar, and on this latter web is supported a presser foot 64. The web 63 has a vertical slot 65 therethrough which accommodates the collar 51. This collar fits between the sides of slot 65 with a slight clearance, thereby allowing a slight transverse movement of the lower end of the shoe while permitting a swinging movement in the transverse plane, the collar 51 then acting as a pivot.

In the assembly of the parts the shoes 58 are positioned close together at their lower ends, as indicated in Fig. 7, but the side edges of each shoe taper inwardly and upwardly, the upper ends of the shoes being narrower than the lower ends and spaced apart somewhat, as also indicated in Fig. 7.

The entire group of shoes are assembled as a unit with a pair of sheet metal plates 66 of a length substantially equal to the length of the clamp and a pair of resilient non-metallic blocks Bl, preferably formed of soft rubber, which are of the same length as the metal plates. Each of the resilient blocks is secured on one side to the web (ill and on the other side to a plate 66. If rubber is used the union is effected by vulcanizing the rubber to the metal parts. At the time of assembly the blocks 51 are rectangular in cross section and are in their natural unstressed state. When the unit is inserted into the hollow bar 2| however each shoe is displaced upwardly with respect to the plates 66 so as to put the rubber blocks underan initial stress. To this end the inner surfaces of walls and 5| are recessed to provide shoulders against which the upper edges of the plates 66 bear. The flange 52 of the shoe bears on the flange 54 of wall 50. Fig. 8 shows the normal position of the parts.

When in the operation of a machine the clamp descends and engages a pile or piles of paper and the flange 62 is pushed away from the flange 5e, pressure is at once exerted upon the pile due to the initial stress in the rubber blocks. As the clamp continues to descend the shoes rise further relative to the hollowhar, as indicated in Fig. 9, and the rubber blocks are placed under greater stress. This effectmay continue until the presser feet fi l strike the lower surfaces of the flanges Although we prefer to employ two rubber blocks only and a single pair of plates 66, it will be obvious that one, twoor more shoes may be used with a pair of blocks, also that the number of plates may or may not correspond with the number of blocks. It is convenient however to have a single assembly of shoes, plates and blocks for the entire clamp.

The machine can handle a number of stacks or piles of, paper, as indicated at P in Figs. 3 and 5. The stacks should be .of approximately equal height. The presser foot 64 of each shoe is normally separated from the flanges 54 and 55 a distance of approximately one-half inch. Hence that much deviation in the heights of the compressed piles is permissible. When, as indicated in Fig. 5, piles that are higher on one side than on the other are encountered the individual shoes are free to tilt in the transverse plane, the resil,

ient blocks 61 resisting that movement in the same way that they resist vertical movement, and returning the shoes to normal position when the clamp is raised free of the work. I

It is not to be inferred however that the clamp is limited in use to a plurality of small piles orto trimming booklets and the like.

Another important use is the effective gripping of wide piles of calendered stock wherein the edges are oftentimes of greater thickness than the central portions of the sheets. In such papers, the cumulative effect of thickened edges in a 4" or 5" pile amounts to increases in the order of flsth inch in total height, so that a rigid clamp cannot possibly hold the thinner .areas of the pile firmly enough to prevent slippage during the cutting action. I But with our structure of individual pressure shoes, the variation in pile height from one side to the other can be as much as without loss of clamping effect. ability of the shoes to tilt slightly produces an even distribution of pressure all along the pile regardless of whether it presents a concave, convex, undulating or sloping surface to the clamp.

Having thus described our invention we claim:

1. In a, paper cutting machine, a table, a frame comprising side members extending upwardly above the tableat either side thereof, a paper clamp, pull bars attached to the ends of said clamp ,at points spaced above the active surface of the clamp a distance at least equal to the stroke of the clamp, said pull bars being entirely enclosed within the frame side members for a distance above the table at least equal to said stroke, and operating means connected with the pull bars below the table.

2. In a paper cutting machine, a table, a frame comprising side members extending upwardly above the table at either side thereof, side guides flush with the inner surfaces of said frame side members and extending forward substantially to the line of cut, a paper clamp, pull bars for said clamp attached to the ends thereof, said frame side members having vertical grooves therein in which the pull bars are slidably mounted, said grooves being closed by said side guides for a.distance above the table at least equal to the maximum pile height, and operating means connected with the pullbars below 0 said table.

3. In a paper cutting machine, a table, a frame comprising side members extending upwardly above the table at either side thereof, a. paper clamp, pull bars slidably mounted in said frame members,; connections between the ends of said clamp and said pull bars, said connections being located above the active surface of the clamp a distance at least equal to the stroke of the clamp, said pull bars being entirely enclosed within the frame side members above the table for a distance at least equal to the maximum height of the pile, and operating means connected with said pull bars below the table.

4. In a paper cutting machine, a table, a frame comprising side members extending upwardly above the table at either side thereof, a paper clamp, fiat sided pull bars for the ends of said clamp attached to the ends thereof at points spaced above the working surface of the clamp, said frame side members having vertical holes therethrough spaced from the inner surfaces of the side members, said holes being of the same cross sectional shape as said pull bars and receiving said pull bars with a sliding fit, and op- Further, the

erating means connected with the pull bars below said table.

5. In a paper cutting machine, a table, a frame comprising side members extending upwardly above the table at either side thereof, a paper clamp arranged between said side members and having bearing at its ends against said side members, pull bars at either side of the machine attached to the said clamp at points spaced above the working surface of the clamp, said pull bars having a sliding fit within vertical holes in the side frame members spaced from the bearing surfaces thereof, and operating means connected with the pull bars below the table.

6. In a machine of the class described, a paper clamp, counterbalancing means tending to lift the clamp, a power driven rock shaft adapted when oscillated in one direction to lower said clamp and when oscillated in the other direction to permit said counterbalancing means to raise the clamp, a continuously rotating shaft, a crank arranged to swing about the axis of said rotating shaft and having an operative connection with said clamp, and means under control of the operator for communicating power to said crank from said rotating shaft.

'7. In a machine of the class described, a paper clamp, counterbalancing means tending to lift the clamp, a power driven rock shaft adapted when oscillated in' one direction to lower said clamp and when oscillated in the other direction to permit said counterbalancing means to raise the clamp, a continuously rotating shaft, and means comprising a friction clutch under the control of the operator for momentarily connecting said rotating shaft with said clamp to move it in opposition to the action of said counterbalancing means.

8. In a machine of the class described, a paper clamp, counterbalancing means tending to lift the clamp, pull bars attached to the clamp and extending downwardly therefrom at opposite sides of the machine, a power driven rock shaft adapted when oscillated in one direction to impart lowering motion tosaid pull bars simultaneously and when oscillated in the other direction to permit said counterbalancing means to raise the clamp, a continuously rotating shaft, a lever swiveled on said shaft and having operative connection with one of said pull bars, pedal means for swinging said lever to exert a downward pull on one of said pull bars, and a friction clutch also operated by said pedal for connecting said rotating shaft and said lever to add a servo effect to the pedal pressure.

9. In a machine of the class described, a. paper clamp, power means for automatically operating said clamp in conjunction with the paper cutting operation, and manually controlled means for operating the clamp independently of said automatic means, said manual means comprising a friction clutch and a pedal for operating said clutch, the degree of pressure exerted upon the pedal controlling the friction in the clutch, whereby the operator is enabled to gauge the clamp action by the feel of the pedal.

10. In a machine of the class described, a paper clamp, power means for automatically operating said clamp in conjunction with the paper cutting operation, and manually controlled means for operating the clamp independently of said automatic means, said last named means comprising a continuously rotating shaft, a lever swiveled thereupon and operatively connected with the clamp, a drum secured to the shaft, a clutch shoe pivotally mountedon said lever, and a pedal arranged to swingsaid shoe into gripping relation with said drum.

11. In a machine of the class described, a clamp structure comprising a-series of shoes formed of rigid material the lower ends of which are adapted to contact the work, means for guiding the'shoes to permit vertical movement of each shoe relative to an adjacent shoe and a slight tilting of the individual shoes in a transverse plane, and separate resilient non-metallic means for each shoe for opposing relative upward movement of said shoes as well as tilting movement.

12. In a machine of the class described, a clamp structure comprising a series of shoes formed of rigid material the lower ends of which are adapted to contact the work, means for guiding the shoesto permit vertical movement of each shoe relative to an adjacent shoe and a slight tilting of the individual shoes in a transverse plane, and separate resilient means for each shoe adapted and arranged to oppose the individual movement of said shoes both vertically and angularly in the transverse plane.

13. In a machine of the class described, a clamp structure comprisinga series of shoes the lower or work contacting ends of which are arranged close together, the side edges of each of said shoes being inclined upwardly toward each other whereby the upper ends of the shoes are spaced apart, means for guiding said shoes to permit both vertical movement and sidewise tilting movement, and resilient means attached to said shoes and to said guiding means adapted to oppose said vertical and tilting movements.

14. In a machine of the class described, a clamp structure comprising a series of metal shoes the lower ends of which are adapted to contact the work, a vertically movable horizontally disposed hollow bar in which said shoes are mounted, guiding means having a vertical guide surface in said bar along which said shoes move, soft rubber blocks vulcanized to said shoes and to said guiding means, whereby downward movement of the clamp against the work pile causes the individual shoes to stress said rubber blocks.

15. In a machine of the class described, a clamp structure comprising a series of metal shoes the lower ends of which are adapted to contact the work, a vertically movable horizontally disposed hollow bar having interior front and back parallel vertical walls, each of said shoes having a portion of I-shape cross section slidably mounted between said walls, rubber blocks vulcanized to the opposite surfaces of the web of said I-shaped portion and to the adjacent wall of the hollow bar, whereby the upward movement of each shoe relatively to said bar stresses said rubber blocks.

16. In a machine of the class described, a clamp structure comprising a hollow horizontal bar movable up and down, said hollow bar having interior front and back parallel vertical walls, a series of metal shoes slidably mounted between said walls, said shoes having upwardly tapering side edges by virtue of which they are spaced apart slightly at their upper ends, sheet metal plates against which the front and rear surfaces of said shoes bear, soft rubber blocks vulcanized to said shoes and to said plates, whereby the plates, blocks and shoes may be assembled as a unit, and abutments for said plates and shoes in said hollow bar whereby the rubber blocks may be placed under initial stress.

17. In a machine of the class described, a clamp structure comprising a hollow horizontal bar movable up and down, said hollow bar having interior front and back parallel vertical walls, a series of metal shoes slidably mounted between said walls, and having presser feet below said walls, those portions of each shoe which are mounted between said walls being I-shape in transverse vertical section, sheet metal plates against which the flanges of the I-section of each shoe bear and by which the shoes are guided, rubber blocks positioned between the webs of the shoes and said plates and being vulcanized to the webs and plates, stop surfaces against which the plates bear upwardly, and stop surfaces limiting the downward movement of the shoes, said hollow bar having a detachable wall permitting the plates, rubber blocks and shoe to be inserted or withdrawn as a unit.

18. In a machine of the class described, a clamp structure comprising a hollow horizontal bar movable up and down, said bar having interior front and back parallel vertical walls, a series of metal shoes having bearing upon said walls permitting movement of the shoes in a transverse vertical plane, the upper ends of said shoes being spaced apart transversely of the bar, vertical guide means for the lower ends of said shoes permitting pivotal action, and resilient means within said hollow bar for opposing the transverse tilting movement of said shoes as well as their upward movement relatively to the bar.

WILLIAM R. SPILLER. JOHN R. LEHMAN. 

